Water hammer is a natural phenomenon that occurs when a tap is first turned and water flows through a pipe and suddenly stops or changes direction.
It isn’t intrinsically dangerous, but when pressures exceed the design limits of a system the shockwave can cause structural damage, leaks, and breaks in the water pipes.
Mr Clarke is investigating the current measurement of the speed at which surges occur within water networks, known as ‘wave speed’, and how that is used to design and maintain water infrastructure.
“The noise that you hear rattling down your pipes at home after brushing your teeth or washing your dishes is a sign of water hammer,” said Mr Clarke.
“A key factor in determining the need for water hammer mitigation measures rely on the current information available to the industry, which is based on the Joukowsky Equation, which predates the existence of modern polyethylene pipes.
“Using high resolution pressure data from parts of Unitywater’s network to observe transient pressure waves, this research will provide guidance for both new and existing infrastructure on surge mitigation equipment, either bolstering confidence in existing processes and infrastructure or leading industry-wide change.”
Water networks across the globe rely on surge mitigation vessels, which use large bladders connected to piping infrastructure to absorb excess pressure and are designed using the Joukowsky equation.
Mr Clarke’s PhD research project will be supervised by Dr Luke Verstraten, who specialises in the hydraulics of drainage systems, and a steering committee of industry and academic experts.
Unitywater Executive Manager Sustainable Infrastructure Solutions, Mike Basterfield, said Unitywater is pleased to support innovation within the infrastructure space.
“Supporting this research project is a win-win for Unitywater, as either of the two possible outcomes will positively impact the way we plan for, and design this infrastructure in the future,” Mr Basterfield said.
“In the last decade we have installed almost 700 kilometres of stronger and more flexible high density polyethylene pipes across our network providing a range of benefits that include a longer life than traditional materials, ease of installation and local manufacturing capability.
“The research project is the first of its kind, and if Mr Clarke’s theory is correct, will impact water hammer mitigation design strategies across global water networks.”
Mr Clarke’s research will take place in four stages, first modelling simulations to estimate pressure behaviour in complex pipe environments.
“We will collect flow and pressure data from the Unitywater network to validate simulations, before updating the current design methods of HDPE to reflect data validated by the real-world network behaviour,” said Mr Clarke.
“We’re keen to test the potential for machine learning to simplify the process before developing a new technical standard for pipeline design.
The project will be guided by a Project Steering Committee with members from both Unitywater and University of the Sunshine Coast and is set to continue through to mid-2027.
